Portable electronic devices such as cellular phones may be used with detachable or wireless electronic accessories such as wireless headsets. Such electronic accessories typically need to be charged in order to have sufficient power for normal operation. FIGS. 1A-C show conventional arrangements for charging wireless headsets.
FIG. 1A shows an example conventional arrangement in which a headset 112 is charged through a charger 111. Charger 111 includes, for example, a connector 114 to be plugged into headset 112, an AC adapter 118 to be plugged into a wall outlet (or an outlet of an extension cable connected to a wall outlet), and a cable 116 connecting connector 114 and AC adapter 118.
In such an arrangement, it is not possible to charge headset 112 when there is no wall outlet nearby, such as when a user of headset 112 is riding a car, or when the user does not carry charger 111 with him/her. Further, after charging headset 112 at a certain wall outlet, a user of headset 112 is typically required to return to the location of the wall outlet to pick up headset 112 and charger 111. Therefore, much inconvenience, inflexibility, and immobility may be involved in such an arrangement. Still further, AC adapter 118 may be bulky, and cable 116 may be long and prone to tangle. As such, it is typically inconvenient for the user to carry and to handle charger 111, in addition to carrying and handling another charger for a cellular phone with which headset 112 pairs and works.
FIG. 1B shows another example conventional arrangement in which a headset 122 is charged through a charger 121 and a cradle 120. Charger 121 includes, for example, a connector 124 to be plugged into cradle 120, an AC adapter 128 to be plugged into a wall outlet (or an outlet of an extension cable connected to a wall outlet), and a cable 126 connecting connector 124 and AC adapter 128. Cradle 120 includes, for example, a port to receive connector 124, conductive contacts to transmit power to headset 122, and appropriate structural components to mechanically support headset 122 while disposed in cradle 120.
Such an arrangement may provide mechanical support and protection for headset 122 during charging. However, such an arrangement again limits the charging of headset 122 to locations near a wall outlet. Further, cradle 120 represents another bulky component that requires the user to carry and handle if the user wishes to charge headset 122 while away from home.
FIG. 1C shows still another example conventional arrangement in which headset 132 is charged by a computer 140 through a USB cable 131. USB cable 131 includes, for example a USB connector 138 to be plugged into a USB port 142 of computer 140, and a connector 132 to be plugged into headset 132. When connected with headset 132, computer 140 first establishes a host-client relationship with headset 132 and then transmits power to headset 132. In such a USB host/client pairing, a USB host and a USB client are typically required, with computer 140 performing the function of the USB host and headset 132 performing the function of the USB client in the example of FIG. 1C.
In such an arrangement, headset 132 cannot be charged when there is no available USB host device such as computer 140 nearby. Further, a USB host device such as computer 140 typically needs to be turned on in order to establish a host-client relationship with headset 132, and a headset 132 user may be required to wait a significant amount of time for the USB host device to turn on. Still further, if a user charges headset 132 at a USB host device that is not portable or not carried with the user, the user is typically required to return to the USB host device to pick up headset 132. If no USB host is available, headset 132, which assumes the role of a USB client in receiving charge from another device in the example of FIG. 1C, cannot be charged. Therefore, much inconvenience may be involved in such an arrangement.